MOSCOW, June 18 (Reuters) - Russia’s top oil producer Rosneft said on Thursday it had signed a preliminary contract to supply oil to refineries operated by Venezuelan state company PDVSA.

“The contract, intended for one year with the possibility of further extensions, involves a joint analysis of possible deliveries of Rosneft Urals oil to Venezuela for the purpose of processing in PDVSA refineries,” Rosneft said in a statement.

The company gave no further details and said price and volumes would be decided in future negotiations.

The deal is the latest in a series of join ventures between Venezuela and Rosneft as the Russian oil major seeks to raise its international presence.

Rosneft agreed to invest around $14 billion in the South American country’s oil and gas sector in May and is negotiating a $5 billion financing deal with PDVSA, a source said on Wednesday. (Reporting by Olesya Astakhova and Jack Stubbs; Editing by David Holmes)